Friction engaging device and control means therefor



y 2, 1953 H. E. CARNAGUA EI'AL 2,538,185

FRICTION ENGAGING DEVICE AND CONTROL MEANS THEREFOR Original Filed Dec. 16, 1943 PatenteclMay 12, 1953 FRICTION ENGAGING DEVICE AND CON- TROL MEANS THEREFOR- Harold E. Carnagua and Donald W. Kelbel, Muncie, Ind., assignors to Borg-Warner Corporation, Chicago, 111., a corporation of Illinois Original application December 16,1943, Serial No.

Divided and this application October 31, 1946, Serial No. 706,960

9 Claims.

'This invention relates to friction engaging devices and control mechanisms therefor.

It is an object of our invention to provide a compact arrangement of a plurality of frictionally engaging devices and more particularly it is an object to provide such an arrangement in which the frictionally engaging devices are hydraulically operated.

It is still more particularly an object of the present invention to provide a hydraulically operating arrangement for a pair of such frictional devices in which a single piston is used for en gaging both of the devices, each to the exclusion of the other, whereby the two devices are mutually exclusively operable.

This application is a division of our copending application, Serial No. 514,464, filed December 16, 1943, now Patent No. 2,414,359.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above stated objects and such other objects as will appear from the following description of a certain preferred embodiment which is illustrated in the accompanying drawing, wherein:

Fig. 1 is an end elevation, partly in section, of a brake arrangement and control mechanism therefor embodying the principles of invention, said section being taken on line I! of Fig. 2; and

Fig. 2 is a longitudinal sectional view of the brake arrangement and control mechanism therefor shown in Fig 1.

Like characters of reference designate like parts in the several views.

Referring to the drawing, a pair of friction engaging devices, and control mechanisms therefor, are illustrated in a preferred embodiment of the invention as comprising a pair of brakes l8 and 2-2. Said brakes comprise a cylinder 18 formed in housing 1! in which is a double acting piston 79. Itwill be noted that the cylinder :3 is disposed radially of two brake drums 36 and 3! and off their peripheries. The ends of cylinder I8 are closed off by end platestl) and H and resilient means such as coil springs 82 and 33 are compressed between piston "l9 and end plates 80, and 8i. The pressure of springs 82 and lit is not taken directly by piston l9 but by apertured stampings or abutments M and 85 each of which is anchored to a piston rod 86 and 81' respectively. The stampings 84 and 85 are annular in shape and, in the assembly shown, are separate from the piston 1'9, the outer peripheries of the stampings contacting the opposite ends of the piston 19, so that the piston may move relative to the stampings during the operation of the brake mechanism as will now be described. The rods are provided with shoulders 88 and 89, respectively, which limit the inward movement of the rods, the shoulder 88 on the rod 86 also limiting movement of the stamping 84 to the right (Fig. 1) and the shoulder 89 also limiting movement of the stamping 85. to the left (Fig. 1). In order to move one of the rods, for example rod 31, outward, iiuid under pressure is admitted through a conduit 90 into the opposite half of cylinder '18 and the fluid then passes through the apertures 84a in the stamping 84 to piston 19, thereby forcing the piston to the right as viewed in Fig. 1 against stamping B5 to move rod 81 outward. A similar arrangement of parts is used to cause piston rod 86 to be moved to the left as shown in Fig. 1. More specifically, upon the release of fluid under pressure acting in the cylinder to move the stamping 8d, movement of the rod 86 outward may be effected by the admission of fluid under pressure through a conduit )2 into the other half of the cylinder l8 and the fluid then passes through the apertures 85a in the stamping B5 to the piston is to force the piston to the left as viewed in Fig. 1 against stamping 84 to move rod 86 outward.

The movement of each rod is transmitted to the respective brakes by suitable linkage. As an example of one form of linkage, rod 87 is connected through a {3111*3111-5101} connection. 9! to a bell crank 92 which is pivoted at 93 to an anchor block for a brake band 94. Said brake band 94 cooperates with drum 36 of brake 18. A spring 95 tensioned between housing H and 8. lug 96 on hand 94 tends to rotate the end secured thereto in a counterclockwise direction as viewed in Fig; 1. The opposite end 9? of brake band 94 is secured to an anchor block 98 which is pivotally connected at 99 to a tension rod we, said rod being pivoted at its opposite end it! to bell crank 92. It will be apparent from the arrangement of the various links and anchor blocks that when piston rod s1 is moved to the right as viewed in Fig. 1 the ends of the brake band will be drawn together to effect its tightening about its associated drum, thereby causing the brake to become operative to arrest the rotation of shaft 35. It will also be observed that spring 83 in cylinder l9 and spring 95 will tend to release the brake. A similar arrangement may be used to operate the brake 22.

It will be observed that the operating linkages of brakes i8 and 22 are of the servo type, thus requiring less pressure in the operating cylinder. As the brake bands take hold, they will rock around and lock with a greater force than that applied by the oil pressure alone. The arrangement of the piston 19 with the brakes l8 and 22 is quite compact and the arrangement is further advantageous in that the single piston 19 is adapted for operating both of the brakes I8 and 22 mutually exclusively of the other.

It may be noted that passages ill, 16, and I? for fluid under pressure are shown in Fig. 2, the passages l0, l6 and TI respectively communicating with clutches and a torque converter of a transmission shown and described in our United States Patent No. 2,414,359. Accordingly, while these passages are shown in Fig. 2, the passages do not communicate with the ports 90 and E02 in Fig. 1 and are not necessary for the operation of the brake mechanism shown in Figs. 1 and 2.

We wish it to be understood that our invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be apparent to those skilled in the art that changes may be made without departing from the principles of the invention.

We claim:

1. A control device for a plurality of friction-engaging means including mutually exclusively operable elements disposed exteriorly of said device comprising means forming a chamber, a piston in said chamber, and a pair of piston rods extending into said chamber and adapted to be actuated by said piston, each rod also extending exteriorly of said device and being connected to operate one of said mutually exclusively operable elements, the operative relation between said pistons and piston rods being such that movement of said piston in one direction will actuate one of said elements away from the other and movement of the piston in the opposite direction will actuate the other of said elements away from said one element, and spring means on said rods and urging the rods toward each other.

2. A control device for a plurality of frictionengaging means including mutually exclusively operable elements disposed exteriorly of said device comprising means forming a chamber, a piston in said chamber, a pair of piston rods extending into said chamber, each rod also extending exteriorly of said device and being connected to operate one of said mutually exclusively operable elements, and means for effectively connecting said p ston and rods whereby movement of said piston in one direction will actuate one of said rods but not the other and movement in the opposite direction will actuate said lastnamed rod but not said first-named rod.

3. A control device for friction-engaging means including mutually exclusively operable elements disposed exteriorly of said device comprising a chamber, a piston in said chamber, a pair of piston rods extending into said chamber, each rod also extending exteriorly of said device and being connected to operate one of said mutually exclusively operable elements, and an abutment on each rod in the path of movement of the piston, said piston being urged against one or the other of the abutments, by the establishment of a difference of pressure on the sides of the piston, to move one of said rods but not the other of said rods.

4. A fluid-pressure responsive control device for a plurality of friction-engaging means including mutually exclusively operable elements disposed exteriorly of said device comprising a chamber having end walls in fixed spaced relation, a piston in said chamber, a pair of piston rods extending through said walls and into said chamber, each rod also extending exteriorly of said device and being connected to operate one of said mutually exclusively operable elements, and an abutment on each rod in the path of movement of the piston, said piston being urged against one of said abutments to actuate the corresponding piston rod and element by fluid pressure on one side of the piston and being urged against the other of said abutments "to cause movement of the corresponding rod and element by fluid pressure on the other side of the piston.

5. A fluid-pressure responsive control device for a pair of friction-engaging means including mutually exclusively operable elements disposed exteriorly of said device comprising means forming a. cylindrical chamber having spaced end walls, a piston in said chamber, a pair of piston rods extending through said walls into said chamber from opposite ends thereof, each rod also extending exteriorly of said device and being connected to operate one of said mutually exclusively operable elements, and an abutment on each rod in the path of movement of said piston, said piston being urged against one of said abutments in one direction to cause a movement of the corresponding rod and element by the establishment of pressure on one side of the piston and being urged against the other of said abutments in the other direction to cause a movement of the corresponding rod and piston by a. pressure onthe other side of said piston and springs within said chamber and acting against said end walls and said abutments to maintain one of said rods in retracted position and to yieldingly resist movement of the other of said rods by said piston, during movement of said piston.

6. A control device for mutually exclusively operable elements disposed exteriorly of said device comprising means forming a chamber, a piston in said chamber, a pair of piston rods extending into said chamber from opposite ends thereof, each rod also extending exteriorly of said device and being connected to operate one of said mutually exclusively operable elements, an abutment on each rod in the path of movement of said piston, said piston coacting with one of said abutments to cause movement of the corresponding rod when moved in one direction and coacting with the other of said abutments to cause movement of the other rod when moved in the opposite direction, a spring acting between each of said abutments and the adjacent end of said chamber for yieldingly holding the corresponding rod in its inoperative position, and means engaging said rods and spaced walls of said means forming said chamber for limiting movement of each rod into the chamber.

'7. A control device for mutually exclusively operable elements disposed exteriorly of said device comprising means forming a chamber, a piston in said chamber, a pair of piston rods extending into said chamber from opposite ends thereof, each rod also extending exteriorly of said device and being connected to operate one of said mutually exclusively operable elements, an abutment on each rod in the path of movement of said piston, said piston being urged against one or the other of said abutments by the establishment of a difierence of pressure on the sides of the piston, a spring between each of said abutments and the adjacent end of said chamber ioryieldingly holding the rod in its retracted position, and means on each rod and engageable with spaced walls of said means forming said chamber for limiting the movement of each rod into the chamber.

8. Fluid-pressure responsive control means for two brakes including brake drums which are disposed coaxially and side by side and a band for engaging each of the drums, comprisin casing means forming a chamber spaced radially of said drums and disposed off their peripheries, a piston in said chamber, a pair of piston rods extending into the chamber from opposite ends thereof, each of said rods being connected to operate one of said brake bands, and an abutment on each rod in the path of movement of the piston, said piston coasting with one of said abutments when the piston is moved in one direction for thereby actuating the corresponding shift rod and engaging the corresponding brake and similarly engaging the other brake when the piston is moved in the opposite direction, said piston being urged against one or the other of said abutments by the establishment of a difference of pressure on the sides of the piston to move one of the shift rods but not the other of said shift rods.

9. Fluid-pressure responsive control means for a plurality of brakes including brake drums which are disposed coaxially and side by side and a band for engaging each of the drums, comprising casing means forming a chamber spaced radially of said drums and disposed off their peripheries, a piston in said chamber, a pair of piston rods extending into said chamber from opposite ends thereof, each rod being linked with one of said brake bands for operating the band, and an abutment on each rod in the path of movement of said piston, said piston when moved in one direction engaging one of said abutments and actuating the corresponding rod and, brake band and when moved in the opposite direction similarly actuating the other brake band, and a spring disposed between each of said abutments and the adjacent end of said chamber for holding the corresponding piston rod in its retracted position, and means on each rod and engageable with spaced walls of said chamber means for limiting the movement of each rod into the chamber.

HAROLD E. CARNAGUA. DONALD W. KELBEL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 671,747 Ball Apr. 9, 1901 952,794 Farmer Mar. 22, 1910 1,239,252 Baukat Sept. 4, 1917 1,309,611 Bungay July 1.5, 1919 1,590,226 Boisset June 219, 1926 1,745,346 Anderson Feb. 4, 1930 2,275,722 Bowen Mar. 10, 1942 2,330,198 Banker Sept. 28, 1943 2,370,484 Nabstedt Feb. 27, 1945 

